1. Field of the Invention
The invention relates to a panel, in particular a floor panel, with a core of a wood material or wood material/plastic mixture, a top side and an underside, wherein the panel has a profile corresponding to one another on at least two side edges lying opposite one another, such that two identically embodied panels can be joined and locked to one another through an essentially vertical joining movement in the horizontal and vertical direction. The locking in the horizontal direction can be effected by a hook connection with an upper locking section having a hook element and a lower locking section having a hook element. The locking in the vertical direction can be effected by at least one spring element that can be moved in the horizontal direction and during the joining movement the at least one spring element snaps in behind a locking edge extending essentially in the horizontal direction.
2. Discussion of Background Information
A panel with a locking in the vertical direction is known, for example, from EP 1 650 375 A1. This type of locking realized with this panel is preferably provided on the transverse side of floor panels. However, it can also be provided on the long side or on the long side as well as on the transverse side. The spring element is composed of plastic and is placed in a groove running horizontally on one of the side edges and chamfered on its top side. Similar to a door latch, through the chamfer the spring element is pressed inwards into the groove by the panel to be newly placed, when the underside thereof meets the chamfer and is lowered further. When the panel to be newly placed is completely lowered onto the base, the spring element snaps into a groove inserted horizontally in the opposite side edge and locks the two panels in the vertical direction. Special injection molds are necessary for the production of this spring element, so that the production is relatively expensive. Furthermore, a high-quality plastic must be used in order to provide sufficient strength values, which makes the spring element even more expensive. If plastics are used with strength values that are too low, this leads to relatively large dimensions of the spring elements, since only thereby is it ensured that corresponding forces can be generated or transferred.
Additional expenses result because the locking element is embodied as a separate component. The production of the locking element is carried out for technological reasons spatially separately from the panels, so that an integration into the continuous production process, in particular for floor panels, is likely to be impossible. Through the different materials, wood material on the one hand and plastic on the other hand, the adjustment of production tolerances from two separate production processes is complex and cost-intensive. Since the locking in the vertical direction would be ineffective if the locking element was missing, in addition this must be secured from falling out of the groove inserted in the side edge in the further production process and during transport. This securing is also complex. Alternatively thereto, the locking element could be made available to the consumer separately.
The floor panels under consideration are being laid with increasing frequency by do-it-yourselfers, so that, in principle, it is possible due to a lack of experience for the required number of locking elements to be initially miscalculated and not obtained in sufficient quantity in order to be able to lay a room completely. Furthermore, it cannot be ruled out that the do-it-yourselfer upon placing the spring element makes a mistake that means that precise locking is not possible and the bond separates over time, which is then wrongly attributed by the consumer to the quality supplied by the manufacturer.
A panel is known from DE 102 24 540 A1, which is profiled on two side edges lying opposite one another such that hook-shaped connection elements are formed for locking in the horizontal direction. For locking in the vertical direction, positive engagement elements spaced apart from one another horizontally and vertically are provided on the connection elements and undercuts corresponding thereto are provided with respectively one horizontally aligned locking surface. The transverse extension of horizontally aligned locking surfaces of this type is approx. 0.05 to 1.0 mm. The dimensioning must be so small in order for the joining of two panels to remain possible at all. However, this inevitably means that only low, vertically aligned forces can be absorbed, so that production must be carried out with extremely low tolerances, in order to ensure that the connection does not spring open with normal stress in the case of even slight irregularities in the floor and/or soft subfloors.
The unpublished application DE 10 2007 015 048.4 describes a panel in which the locking is effected in the vertical direction through a spring element moveable in the horizontal direction. With a joining movement, the spring element snaps behind a locking edge extending essentially in the horizontal direction. The spring element is embodied from the core through a horizontal and vertical cut and connected to the core on at least one of its two ends. The horizontal and vertical cut renders possible the spring movement of the spring element necessary for the production of the locking.
However, this locking is not suitable for thinner panels with a board thickness of approx. 4 mm to 8 mm.
Based on this problem, the panel described at the outset is to be improved.